A trophic level is each step in a food chain that demonstrates the transfer of energy.
A trophic level is any feeding level in a food chain through which energy in the form of food is transferred in an ecosystem. A food chain contains five main trophic levels which are; (i) primary producers (autotrophs; plants and algae), (ii) primary consumers (herbivores), (iii) Secondary consumers (carnivores and omnivores), (iv) Tertiary consumers (carnivores and omnivores) and (v) Apex predators.
Answer:
Island finches did not have beaks of the same size and shape
Explanation:
This is the evidence of variation, and therefore proof that the finches were able to survive the selective pressure by adapting their beaks to different feeds. Therefore finches that were able to adapt adjusted their beak shapes to the selecting pressure 'feeds' in the environment, and are naturally selected, and therefore adapted and evolved with time .While those without the surviving beaks lost out.
Thus changes in selection pressure, necessitated corresponding change in the beaks shape for adaption to survive( due to variation, ) and therefore natural selection for evolution
Cells are the basic unit of structure and function in living organisms
